package com.itheima.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.BaseContext;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

/**
 * 检查用户是否完成登录
 */
//用于将此类声明为过滤器类，filterName为名称，urlPatterns：过滤的URL
@WebFilter(filterName = "LoginCheckFilter", urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {
    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) servletRequest;
        HttpServletResponse res = (HttpServletResponse) servletResponse;

        //1、获取本次请求的URI
        String requestURI = req.getRequestURI();
        log.info("拦截到请求:{}", requestURI);
        //定义不需要处理的请求路径
        String[] strings = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                "/user/sendMsg",
                "/user/login",
                "/doc.html",
                "/webjars/**",
                "/swagger-resources",
                "/v2/api-docs"
        };
        //2、判断本次请求是否需要处理
        boolean check = check(requestURI, strings);
        //3、如果不需要处理，则直接放行
        if (check) {
            filterChain.doFilter(req, res);
            return;
        }
        //4-1、判断登录状态，如果已登录，则直接放行
        if (req.getSession().getAttribute("employee") != null) {
            log.info(req.getSession().getAttribute("employee").toString());

            Long id = (Long) req.getSession().getAttribute("employee");
            BaseContext.setCurrentId(id);
            log.info("登录用户的id为：{}", id);
            //已登陆
            filterChain.doFilter(req, res);
            return;
        }

        //4-2、判断登录状态，如果已登录，则直接放行
        if (req.getSession().getAttribute("user") != null) {
            log.info(req.getSession().getAttribute("user").toString());

            Long id = (Long) req.getSession().getAttribute("user");
            BaseContext.setCurrentId(id);
            log.info("登录用户的id为：{}", id);
            //已登陆
            filterChain.doFilter(req, res);
            return;
        }
        //5、如果未登录则返回未登录结果，通过输出流方式向客户端页面响应数据
        log.info("用户未登录");
        res.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }

    /**
     * 路径匹配，检查本次检查是否需要放行
     *
     * @param requestURI
     * @param s
     * @return
     */
    boolean check(String requestURI, String[] s) {
        for (String strings : s) {
            boolean match = PATH_MATCHER.match(strings, requestURI);
            if (match) {
                return true;
            }
        }
        return false;

    }
}
